Timing Chain: How Tight Is Too Tight

[Truckedup]

My opinions on tight roller chains, I assume you guys are using roller and not Hyvo, are different based on motorcycle experience. The bikes I race use a roller chain to transmit power from the engine to the clutch..They are double and triple row roller chains..They all have an adjustable tensioner ... If the chain is adjusted too tight, it heats up in operation and leads to roller galling and partial side plate seizure...Otherwords, a slightly loose chain is far better...But the problem is, in my opinion, with OHV V8's, they have no tensioner so the chain must be too tight to avoid flapping around at speed. I know the center are closer than bike primary drives, but wouldn't a tension device be an improvement...?

[Truckedup]

My opinions on tight roller chains, I assume you guys are using roller and not Hyvo, are different based on motorcycle experience. The bikes I race use a roller chain to transmit power from the engine to the clutch..They are double and triple row roller chains..They all have an adjustable tensioner ... If the chain is adjusted too tight, it heats up in operation and leads to roller galling and partial side plate seizure...Otherwords, a slightly loose chain is far better...But the problem is, in my opinion, with OHV V8's, they have no tensioner so the chain must be too tight to avoid flapping around at speed. I know the centers are closer than bike primary drives, but wouldn't a tension device be an improvement...?

[MadBill]

Some years ago, when I failed to source a short chain for my line-bored aluminum BBC, I modified a Chev Cavalier tensioner and grafted it on. I have every reason to think it would have worked well, but subsequently I wished to fit a quick cam access cast aluminum cover which would have needed significant work to clear it so I was able to get a 0.005" short chain instead, which fits just a little loose,
about right I judge for the greater expansion of the alloy block.
.

Chain Tensioner 001.JPG

[Newold1]

Fueling motor cycle parts makes a nice small tensioner I have used on SBC & BBC timing chains for just some hard fit timing set applications.
It can be fitted under most timing covers also.
www.fuelingparts.com

8075-t.jpg

[Kevin Johnson]

Fueling motor cycle parts makes a nice small tensioner I have used on SBC & BBC timing chains for just some hard fit timing set applications.
It can be fitted under most timing covers also.
http://www.feulingparts.com/products/Hy ... nents/8075

[Ron Miller]

Fueling motorcycle parts make a nice small tensioner I have used on SBC & BBC timing chains for just some hard fit timing set applications.
It can be fitted under most timing covers also.
www.fuelingparts.com

8075-t.jpg

Can this be bought separately, what is the part number? All I see is a kit, where can you buy it and how much? Got any installed pictures?

Thanks for looking,

[Kevin Johnson]

The tensioner alone is part 8077; see the instruction pdf on the website.

Part_8077.gif

[cjperformance]

The tensioner alone is part 8077; see the instruction pdf on the website.
Part_8077.gif

Kevin are these a ratcheting type tensioner?
Im sure you know but ratchet tensioners need to have more 'slack' between ratchet locks than normal thermal and load changes can give the chain or the tensioner can run the chain too tight and cause damage.

[Kevin Johnson]

I know the type you mean, Craig. I do not see any mention of that in the instructions. The picture below is highly suggestive that you simply pull the pin. Edit: it looks like you will need to provide an oil supply drilling. I have never used them myself.




Correction: Overview of Feuling Motor Company Hydraulic Inner Cam Chain Tensioner Assembly - 8076
Stock replacement hydraulic cam chain tensioners
* Tensioner housings are precision machined from billet 6061 aluminum, pads are injection molded Nylon with PTFE added to increase wear and friction resistance
* Tensioners are single piston duplicating the output pressure of stock units
Feuling tensioners include ARP® 12-point hardware
* Tensioners fit Feuling, factory and SE 07-16 chain drive plus conversion camplates designed to run the early 99-06 camshafts
Made in the U.S.A.

[cjperformance]

I know the type you mean, Craig. I do not see any mention of that in the instructions. The picture below is highly suggestive that you simply pull the pin.

Ah ! Was thinking they tlook familiar but couldn't pick it, theyre twin cam harley tensioners, i dont have fuelling ones in mine so the different look had me fooled.
They are a hydraulic tensioner.
Have you adapted them into a SBC? Chain pad is way narrow (fueling may be different?) To run a double roller chain, unless you ran a single roller/narrow chain?

[Newold1]

I have used these Fueling tensioners a few times and I can tell you they are not ratcheting tensioners.

[cjperformance]

I have used these Fueling tensioners a few times and I can tell you they are not ratcheting tensioners.

Yes now i have realised they are TC HD tensioners. Hydraulic from engine oil pressure supply, (often pretty low compared to most V8 stuff) plus unless those particular tensioner pads are wider than the ones in my TC then they are no good for any V8 chain i have used.

[Newold1]

Yes these are Harley type replacement chain tensioners but they are different than the factory Harley tensioners. I finish off flat the nylon face flat and even though they are slightly narrower than a chevy double roller chain they seem to track fine and have worked for me in the places I have used them.

[MadBill]

I have used these Fueling tensioners a few times and I can tell you they are not ratcheting tensioners.

Yes now i have realised they are TC HD tensioners. Hydraulic from engine oil pressure supply, (often pretty low compared to most V8 stuff) plus unless those particular tensioner pads are wider than the ones in my TC then they are no good for any V8 chain i have used.

Good point! If they deliver 'adequate' tension with say 25 psi, what happens at 60-70 psi?

Speaking of oil drilling, when I drilled and tapped the mounting holes for the one I added to my BBC, I managed to bore straight into the front main bearing feed passage...

[cjperformance]

I have used these Fueling tensioners a few times and I can tell you they are not ratcheting tensioners.

Yes now i have realised they are TC HD tensioners. Hydraulic from engine oil pressure supply, (often pretty low compared to most V8 stuff) plus unless those particular tensioner pads are wider than the ones in my TC then they are no good for any V8 chain i have used.

Good point! If they deliver 'adequate' tension with say 25 psi, what happens at 60-70 psi?

From http://www.feulingparts.com/sku/8077
Quote "Tensioners are single piston duplicating the output pressure of stock units, "

The hydro units are less prone to wear than the early TC spring loaded only unit, i can only guess that the Fueling facing material is better than stock HD facing but dont know. Im hazy about these being in my bike, stock cams, springs and idle rpm keep them happy for longer.
I have to say that given the strength/size of these (i have not used fueling ones) that if you turned a decent solid roller cammed v8 backward that the chain load would break the tensioner somewhere. The chain weight and possible back loading they are designed for is nothing compared to an average V8, theres no way i would feel comfortable with one of them in my Clevo V8 !